A polycarbonate/magnesium oxide nanocomposite with high flame retardancy

Abstract

A new flame retardant polycarbonate/magnesium oxide (PC/MgO) nanocomposite, with high flame retardancy was developed by melt compounding. The effect of MgO to the flame retardancy, thermal property, and thermal degradation kinetics were investigated. Limited oxygen index (LOI) test revealed that a little amount of MgO (2 wt %) led to significant enhancement (LOI = 36.8) in flame retardancy. Thermogravimetric analysis results demonstrated that the onset temperature of degradation and temperature of maximum degradation rate decreased in both air and N2 atmosphere. Apparent activation energy was estimated via Flynn–Wall–Ozawa method. Three steps in the thermal degradation kinetics were observed after incorporation of MgO into the matrix and the additive raised activation energies of the composite in the full range except the initial stage. It was interpreted that the flame retardancy of PC was influenced by MgO through the following two aspects: on the one hand, MgO catalyzed the thermal-oxidative degradation and accelerated a thermal protection/mass loss barrier at burning surface; on the other hand, the filler decreased activation energies in the initial step and improved thermal stability in the final period.

Influence of the modification, induced by zirconia nanoparticles, on the structure and properties of polycarbonate

“…7 illustrates the relationship between the activation energies and the degree of conversion. The activation energy values of pure PC and its nanocomposites generally show an increase with the degree of conversion and fall within the range of activation energies for PC degradation reported previously [7,26]. The activation energy values of the pristine PC are lower than that of the 98/2 w/w PC-zirconia nanocomposite, but they are almost the same above 40% mass loss.…”

“…PC nanocomposites have shown potential applications in UV protecting sheets and films [1][2][3][4]. There are a number of recent papers reporting on the mechanical properties, thermal stability and flame retardancy of PC nanocomposites containing different metal oxide nanoparticles [5][6][7][8][9][10]. The results indicate that metal oxides have an effect on the morphology, as well as mechanical and thermal behavior of PC.…”

The effect of silica nanoparticles on the morphology, mechanical properties and thermal degradation kinetics of polycarbonate

“…It was generally explained as changes in the degradation mechanism with increasing degree of conversion. Dong et al [23] investigated PC-MgO nanocomposites, and they attributed the increase in activation energy of degradation with increasing degree of conversion to the stable carbonaceous char which protects the polymer from further degradation. They also observed that an increase in MgO content shifted the TGA curves to lower temperatures, and that the initial activation energy values for the PC-MgO nanocomposites were lower than those of pristine PC.…”

Properties of Particleboard Made from Oil Palm Trunks Added Magnesium Oxide as Fire Retardant

“…This is because magnesium oxide acts as a good insulating barrier capable of resisting the heat. 30 Although the control OPT particleboard samples contain silica, it is not good enough to overcome the high temperature exposed on it producing low residue than other samples. The magnesium oxide provides a protective region in the particleboard that enables it to prevent thermal degradation of the sample.…”